Long Term Evolution (LTE) is discussed in Third Generation Partnership Project (3GPP), which is a standardization organization for wireless communication systems. In the LTE, uplink user data is transmitted through Physical Uplink Shared Channel (PUSCH) and quality information, etc. are transmitted through Physical Uplink Control Channel (PUCCH).
Downlink user data is transmitted through Physical Downlink Shared Channel (PDSCH).
A technology called retransmission control has been adopted in the wireless communication systems. In the retransmission control, for example, a base station apparatus transmits user data and each mobile station apparatus transmits (feeds back) a delivery result (Acknowledgement (ACK) or Negative Acknowledgement (NACK)) indicating whether the user data is successfully received. The base station apparatus performs, for example, retransmission of the user data on the basis of the delivery result. The mobile station apparatus transmits the delivery result by using the PUSCH or the PUCCH in the retransmission control.
Since the PUSCH is shared between multiple mobile station apparatuses performing wireless communication, a certain mobile station apparatus cannot occupy the PUSCH. Accordingly, the wireless base station apparatus uses Physical Downlink Control Channel (PDCCH) to transmit a permission to transmit through the PUSCH and each mobile station apparatus can use the PUSCH upon reception of the transmission permission.
Refer to 3GPP TS 36.211 V9.0.0 (2009-12) 5.3 Physical uplink shared channel, 5.4 Physical uplink control channel, and 6.8 Physical downlink control channel and 3GPP TS 36.212 V9.0.0 (2009-12) 5.2 Uplink transport channels and control information.